A number of Sony Xperia Z users have reported their devices suffering from sudden death. Apparently, Sony's flagship has been shutting down for no apparent reason with subsequent efforts to bring it back to life proving unsuccessful, save for a hard reset in a few cases.
There is no particular reason for the occurrence. Some users have blamed low battery for the issue, but others have had their Xperia Z expire with plenty of charge left in its battery.
Sony has acknowledged the issue and promised that a fix is in the works. It will be delivered to the users via an upcoming software update.
Thanks for the tip. Just had to do this to get my xperia z to start working again. Went black during charge and wouldn't turn on or take charge.
Have you tried holding Power and volume button same time for a while to restart charging as shown on YouTube video. It worked for me with my dead phone Xperia XZ1....black screen all of a sudden.
Your comment is in 2017. Now the video on YouTube from an Indian guy says hold the start and volume keys same same time (Pressed) for a while and then it will start. I did with my Xperia XZ1 and it works.